title: The RNA chaperone Hfq regulates expression of fimbrial-related genes and virulence of Salmonella enterica serovar Enteritidis.
abstract: Salmonella Enteritidis is an intracellular pathogen that causes enteritis and systemic disease in humans and other animals. The RNA chaperone protein Hfq mediates the binding of small noncoding RNAs to target mRNA and assists in post-transcriptional gene regulation in bacteria. In this study, we constructed an hfq deletion mutant in S. Enteritidis SE50336 and analyzed the expression of major fimbrial subunits sefA, bcfA, fimA, safA, stbA, sthA, csgA, csgD, and pegA using quantitative real-time PCR. The gene expression of sefA increased about 14-fold in the hfq mutant, as compared with its expression in the wild-type strain. The expression of fimA and pegA did not change significantly, while the expression of the other fimbrial genes was significantly down-regulated in the hfq mutant. The ability of SE50336Δhfq adhering to Caco-2 cells was also reduced as compared with wild-type adherence. The virulence of the hfq mutant was significantly reduced in a 1-day-old chicken model of S. Enteritidis disease, as determined by quantifying the lethal dose 50% of the bacterial strains. We conclude that Hfq critically contributes to S. Enteritidis virulence, likely partially affected by regulating fimbrial gene expression.
authors.affiliation: Ministry of Education Key Lab for Avian Preventive Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Meng
authors.forename: Xianchen
authors.initials: X
authors.lastname: Meng
authors.forename: Chunhong
authors.initials: C
authors.lastname: Zhu
authors.forename: Heng
authors.initials: H
authors.lastname: Wang
authors.forename: Jinqiu
authors.initials: J
authors.lastname: Wang
authors.forename: Jiajia
authors.initials: J
authors.lastname: Nie
authors.forename: Philip R
authors.initials: PR
authors.lastname: Hardwidge
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D018938:Caco-2 Cells; D002645:Chickens; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D035001:Host Factor 1 Protein / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D012480:Salmonella Infections / Q000382:microbiology; D012477:Salmonella enteritidis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D017384:Sequence Deletion / Q000235:genetics
chemical_list: D035001:Host Factor 1 Protein; D036781:Fimbriae Proteins
keywords: Hfq; Salmonella Enteritidis; adhesion; invasion; virulence